Posts Tagged ‘hull forms’

Modern conventional fast ships rarely go over speeds of 30 knots, simply because conventional hull forms do not allow higher speeds without unacceptably powerful and complex powerplant (a la LCS), which then means less volume and displacement avaliable for other necessities. High speeds are also very rarely necessary, which means that most ships can sacrifice high speed in exchange for greater firepower, survivability, or endurance. However, combat and peacetime operations have always required ships capable of achieving high speeds, for purposes such as reconnaissance, surprise attacks and combat in general, especially in littoral waters where small hulls dominate and enemy can appear from basically anywhere. High speed is also desireable for deployment of rapid-response forces as an answer to an unexpected crisis, and as airlift is of limited capacity, high-speed sealift is desireable. This means balancing out requirements for high speed, range and high payload.

In conventional ships, developing ships with higher length-to-beam ratio allows installation of more powerful powerplant for a miniscule increase in drag, thus allowing both longer range and higher top speed. Conventional hull form also has major advantages in range, and in that they can be of basically any size. However, they cannot economically achieve very high speeds, which is why specialized – unconventional – hull forms are required for ships that have such requirement. In all these, the goal is to minimize contact with surface of the water. Hull forms can be divided into: Read the rest of this entry »